Interleukin-4 (IL-4) is a potent cytokine with pleiotropic effects on humoral and cellular immunity, hematopoiesis, and inflammation. Mounting evidence suggests that IL-4 is a central cytokine in allergic diseases. The secretion and function of IL-4 have been studied in a variety of in vitro and in vivo systems, but little is known about the molecular factors regulating its synthesis. The human IL-4 gene has recently been cloned, but there is limited data to date regarding control of its expression. The overall goal of this proposal is to rigorously investigate the transcriptional regulation of the human interleukin-4 gene. We have designed oligonucleotide primers for isolation of the 5'-flanking region of the IL-4 promoter from a human genomic library. We will use a variety of complementary and powerful techniques including single base-pair mutagenesis, DNAse I footprinting, and nuclear protein binding assays to systematically delineate the cis-elements and trans-acting factors involved in both constitutive and inducible expression of the IL-4 gene. We will study expression of the promoter construct and regulatory nuclear proteins in a variety of cell types including murine and human basophils and mast cells. This proposal has the potential to lead to important new insights into the control of IL-4 synthesis while serving as an excellent vehicle to expand the principal investigator's knowledge of and training in immunology and molecular biology.